A lot of people considered it an embarrassment for a player of Dionne's stature to be playing in the IHL, but it makes sense from his point of view. He wasn't getting much icetime with the Rangers, and was scratched for some games, and he understood the reason was that his conditioning wasn't where it needed to be (he had gained some weight that he was having trouble shedding). He thought playing full games in the IHL would get him into game shape better than being used sparingly in New York. Plus, he disliked Michel Bergeron and was happy to get away from the Rangers for awhile (the coach in the minors was his old friend Peter Mahovlich).
He gave it a shot, but just didn't have any gas left in the tank. But it's understandable that he thought he still play, considering that he had scored 31 goals the previous year.